Sure, Darth Vader has the Force. But Deadpool can break the Fourth Wall, and he's (usually) got a nearly unstoppable healing factor. So if the Dark Lord of the Sith met the Merc with a Mouth, who would prevail?

Vader could, but wouldn't. Deadpool is a mercenary, same as Fett, so he would just offer him more money.

Cory Parrish:

Vader would force choke him then vaporize every last molecule of him with his lightsaber.

Austin Sheehan:

Well, Deadpool is completely fictional, so Darth Vader obviously.

Jyri Astokari:

Vader. Lightsaber would melt Pool's weapons, leaving him unarmed. Then it's just matter of time before Vader would slice him to pieces and freeze the sucker in carbonite, or destroy him with some imperialist super weapon. Also magma could come handy.